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black tank wont drain

Ziphead2
Explorer II
Explorer II
I have a 2017 Minnie Winnie and am having trouble with my black tank draining. I dont know if the issue is the gate valve outside that is stuck or what. I let it sit until; next stop about 150 miles. I thought whatever is stuck would work its way out. Before we left i put some chemicals down to include Happy Camper but still no go. I am thinking the gate valve is broken closed? If not I'll have to work my way from the valve to the tank. Any opinions? I am open to any ideas/as always thanks!
15 REPLIES 15

Bobbo
Explorer II
Explorer II
noteven wrote:
I have heard of an instance where the round piece of tank wall that was cut out for the valve with a circle saw got left in the tank.

I can attest that this DOES happen. About 3 years after buying my first RV (a Winnebago) in 2007, I was dumping at home using a FloJet macerator. I had a clear section so I could see when "stuff" stopped being rinsed out. Lo and behold, the circle of plastic that had been cut out of the black tank to attach the toilet dropped into the clear plastic connector.

My black tank drained much better after that.
Bobbo and Lin
2017 F-150 XLT 4x4 SuperCab w/Max Tow Package 3.5l EcoBoost V6
2017 Airstream Flying Cloud 23FB

Ziphead2
Explorer II
Explorer II
Thanks for all the. Comments and ideas! I will let everyone know when I tackle the job Friday. Again thanks for all the ideas!

noteven
Explorer III
Explorer III
I have heard of an instance where the round piece of tank wall that was cut out for the valve with a circle saw got left in the tank. It would get washed into the valve, back up undissolved paper, and stop the flow. It was found by looking in the tank with a boroscope.

“Flushable” wipes aren’t for in a holding tank system.

2 meter wipes (using 2 m or 6 ft of azz wipe) per set is asking for trouble.

If the valve is manual you should feel the difference to how the gray valve operates if it is broken. If it feels like both valve slides are opening the same I would see if someone would look in the tank with a scope.

Grit_dog
Nomad III
Nomad III
And until the OP comes back with more information, this thread is pure speculation.
Nothing like open ended questions to start a good discussion....
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold

dougrainer
Nomad
Nomad
Dusty R wrote:
Look from under neath to see if the slide valve/gate is opening.


Curious. HOW would you be able to see that?????? The only thing visible is the steel rod that comes out and in. IF the steel rod has separated from the valve blade(very common on this type problem) there is nothing to see, unless you have a straight line of sight from the dump cap to that valve. To the OP, IF the rod has indeed separated from the blade AND you have enough room, I drill a 1/4 inch hole on the END(opposite the rod) in the middle of the valve body. Have a 1/4 rod handy and insert into the hole(a little sewage water will dribble out) and use that 1/4 dowel rod to push the blade OPEN and drain the tank. Once drained, flush and then replace the 3 inch valve. Doug

Bionic_Man
Explorer
Explorer
I was worried about that problem on my last trip. Nothing wanted to come out. I tried back filling, and that didn't help. Finally had the dump valve open, and dumped a 8 gallon water container into the toilet, which flushed everything out.

If that doesn't work, and you have matter in the holding tank, and it isn't a matter of the valve being broken, I'd consider trying some Rid-X.
2012 RAM 3500 Laramie Longhorn DRW CC 4x4 Max Tow, Cummins HO, 60 gallon RDS aux fuel tank, Reese 18k Elite hitch
2003 Dodge Ram 3500 QC SB 4x4 Cummins HO NV5600 with Smarty JR, Jacobs EB (sold)
2002 Gulf Stream Sea Hawk 29FRB with Honda EV6010

Dusty_R
Explorer
Explorer
Look from under neath to see if the slide valve/gate is opening.

Terryallan
Explorer II
Explorer II
The flush attachment at wallyworld works really good, and is reasonably priced. About $15.00. It also directs the stream straight back into the sewer pipe. Shoots about 25 feet.
Terry & Shay
Coachman Apex 288BH.
2013 F150 XLT Off Road
5.0, 3.73
Lazy Campers

Grit_dog
Nomad III
Nomad III
You pulled gate valve “open”, nothing came out?
99.9% sounds like broken gate valve to me.
Start there.
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold

ACZL
Explorer
Explorer
OS !
2017 F350 DRW XLT, CC, 4x4, 6.7
2018 Big Country 3560 SS
"The best part of RVing and Snowmobiling is spending time with family and friends"
"Catin' in the Winter"

falconbrother
Explorer II
Explorer II
Go to Walmart and buy the reverse flush thing. It works good. If that doesn't work...oh dear...

richclover
Explorer
Explorer
LouLawrence wrote:
Tank Flush

You can buy an adapter like this and hook up a hose. It water goes into the tank you are OK. If the water just flushes back out the valve is broken and stuck closed.


Get the model with the gate valve.
Rich
2019 RAM 1500 Classic 4X4 Hemi
2021 CanAm Maverick DS Turbo
Southern NV

LouLawrence
Explorer
Explorer
Tank Flush

You can buy an adapter like this and hook up a hose. It water goes into the tank you are OK. If the water just flushes back out the valve is broken and stuck closed.

valhalla360
Nomad III
Nomad III
What are you basing the issue on:
- If it's the pretty lights on the monitor, they always show up as full even after you drained.
- Do you hear anything when you open the valve?
Tammy & Mike
Ford F250 V10
2021 Gray Wolf
Gemini Catamaran 34'
Full Time spliting time between boat and RV